Treatment of hydrocarbon oil



July 2, 1935. VI :PATIEFF TREATMENT OF HYDROQARBON OIL 1Fi15d`Jan. 16,'1933 O0. Oo Gv oanxlo oN. 9. ..8

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i 023.00 JSP-Z OMN EGVBQLLNBD $338930 INVENTOR VLADIMIR IPATIEF'F BY f@ATTO vY Patented July 2, 1935 UNITED, STATES TREATMENT oF HYDRocARBoNon.

' Vladimir Ipatieff, chicago, n1., assignor to Universal Oil ProductsCompany, Chicago, Ill., a corporation of Delaware Application January16,' 193s. serial No. 652,008 t Claims.

This invention relates more particularly to the manufacture ofhydrocarbons of suitable boiling point for use as components of motorfuel.

In a more specic sense the invention has rei"- 5 erence to a processwhich both conserves materials which are ordinarily considered as wasteproducts in cracking processes and at the same time produceshydrocarbons having specially high anti-detonating characteristics.

Owing to the adoption of high compression ratios in automobile enginesto increase their thermodynamic efficiency, a demand hasbeen made uponthe petroleum reiining and other industries which furnish hydrocarbonmotor fuels, for fuels of a high anti-knocking and slow-burningcharacter. The cracking process which generally produces bothunsaturated hydrocarbons and cyclic hydrocarbons due to the primarydehydrogenating and secondary condensing character of the decompositionreactions is employed quite generally to meet the demand for a highanti-knock motor fuel. However, complete control of the proportion ofcyclic hydrocarbons to olens. is not always possible as the character ofthe charging oil varies with the type of crude from which they areproduced, and when intensive cracking conditions are employed in aneiort to increase the amount of cyclic hydrocarbons and hence theanti-knock value, undesirably large losses in gas and coke may beencountered and frequently the amount of oleflns, particularly those ofa highly unsaturated and unstable character, may increase roughly inproportion to the increase in aromatics and other cyclic hydrocarbons.

The fixed gases produced in cracking processes contain notable amountsof the normal oleiins, including ethylene, propylene, and butylenes andother gases oi a more highly unsaturated and still more reactivecharacter such as iso-olefins, acetylene, butadienes, et cetera.Extensive experimenting has been conducted to find Ways of utilizing thereactive constituents of gases from cracking plants and convert theminto more valuable products.

The present process enables the eiective utilization of the olefinicconstituents of cracked gases and similar olefins produced in anymanner.

In one specific embodiment the present invention comprises treatment ofaromatic or similarly reactive cyclic hydrocarbons with olenic orunsaturated gases in the presence of catalytic agents comprisingmixtures of phosphoric and sulfuric acids.

I have determined that better and more controllable results areobtainable when alkylating aromatic or similarly reactive hydrocarbonswith olens of diverse character when using suitably lproportionedmixtures of sulphuric and ph??- phoric acids than when using either acidalo sulfuric acid is a very energetic catalyst for such 5 reactions andcauses thevready combination of normal mono olelns witharomatichydrocarbons to produce valuable alkylated derivatives. In the' case ofmore reactive oleilns such'as iso-olens or di and tri-olens, however,there is a pronounced tendencytoward polymerization so that this type ofchange occurs in preference to the addition of the oleiln molecules tothe aromatics. The polymerization reactions may proceed to the extent offorming polymers of too highmolecular weight and boiling point for usein commercial motor fuels and may even produce gummy and resinouspolymers which are insoluble and entirely objectionable for this reason.

Phosphoric acid on the other hand has a more moderate action in contrastto sulphuric acid, and

lfosters the interaction of the more reactive oleilns with aromaticsinstead of inducing their polymerization. Consequently, by utilizingsuitably proportioned mixtures of sulphuric and phosphoric acids inreactions involving the alkylation of aromatics by diierent types ofolelns such as occur in gases from hydrocarbon oil cracking processes itis possible to obtain a' high percentage of alkylation along with apractical minimum of polymerizing reactions. There is a higher yield ofdesirable low boiling product with the minimum undesirable sulphurcontent. It is not to be inferred, however, that polymerization can beentirely obviated since the catalytic acid mixtures are not misciblewith the hydrocarbons and only multi-phase reactions are possible, whichleaves the question of effective contact between reacting constituentsto the efficiency of mechanical agitation and mixing. '.40

The reactions between olens and aromatics 'in the presence of condensingcatalysts such as types of reacting components form primarily transientaddition compounds with the acid catalysts which then further react toproduce the synthetichydrocarbons and regenerate the acids.

The followingequation represents the course of a typical reactioninduced between a mono-olenn and an aromatic by sulphuric acid:

CgHs CaHs i y CsHLCsHl Propylene Benzol lso-propyl benzol H31 O4 04H!*t* CsHe C43. CHl Iso-butylene Benzol Iso-butyl benzol This equationshows the union of one molecule each of iso-butylene and benzol. Thereactions in both cases may proceed further to the production of di andeven tri-alkyl derivatives, depending upon conditions of operation, therelative proportions of olefins and aromatics and the usual controllingfactors such as temperature, pressure and emoiency and time of contact.

Sulfuric acid which comprises one of the components of the acid mixtureswhich may be employed is sufficiently familiar to those engaged incommercial chemical operations and particular- 1y in petroleumrefineries to require any detailed description of its properties. It maymerely be stated that it is completely soluble in water and that acidsof any strength from a very dilute acid to solid sulfur trioxide areavailable for use. There is evidence of the existence of both a di and amono hydrate corresponding to the following formulas:

SOa-2H2O (Dihydrate) lSO3'H2O (Monohydrate) r The dihydrate correspondsto approximately 30% H2504 solution and the mono hydrate constitutes100% sulfuric acid.

Below is given a tabulation of the known acids of phosphorous along withtheir melting points and temperatures of decomposition:

Acids of phosphorus m. p. C. Dec. C.

H phosphorous HaPOa 26.5 Above m p Ort ohosphorous HsPO: PzOwliO.. 70.200

B phosphoric H4Ps0| PzOi-2Hs0... 55. 0 70 etapbosphoric HPO: PzOrHiO..-Sublimes Orthophosphoric HaPOl P105-3R10-. 38. 6 L o s e s 56 H at 213Of those listed the use of the more ordinary and stable acids ispreferred, to wit. the orthophosphoric acid HsPO4 and theorthophosphorous acid HaPOa, these being used alternatively in differentmixtures though without identically equivalent results. y

In conducting operations leading to the production of hydrocarbonsaccording to the process of the present invention, individual olens ormixtures of oleiins such as occur in gases from oil cracking plants maybe introduced Ainto well tially no deterioration and the sludgesulphuric acid is readily regenerated. When tests have shown that thedesired degree of alkylation of the benzol has taken place, the gasstream may be stopped and the hydrocarbon layer separated from the acid.A

The foregoing procedure is of a very simple character and in commercialpractice may be modified to permit the use of ordinary batch andcontinuous treating plants which are familiar to petroleum refineryoperators. For example,v a mixtureof sulphuric and phosphoric acid andaromatic oil may be circulated by centrifugal pumps taking suctionat'the bottom of a batch agitator and discharging back into the top.Such operation may be conducted to permit the separation and continuousremoval of alkylated aromatics and if necessary the recycling of thegases.

As a further alternative method of operation, an olefinic gas mixture,for example, the fixed gases from an oil 'cracking plant, the requisiteamount of aromatic oil and catalytic acid mixture may be injected into asuitable -mixer positioned in the upper portion of a treating towercontaining filling or spacing material, all reacting components passingdownwardly througha general rule the acid may be cycled for a long timebefore it is contaminated to an extent rendering its use uneconomical.

A large number of examples are available to show the improved resultsobtainable by the use of mixed sulphuric-phosphoric acids according tothe process of the present invention. The following case, involving theinteraction of definite compounds, to-wit, n-butylene, with benzolI isselected principally for the reason that the efficiency of the processmaybe more easily gauged from analytical data. Y

A sexies of experiments were conducted in which n-butylene was passed asa gas into wellstirred mixtures of benzol and differently proportionedacid mixtures. The temperature used in all tests was 60 C. (140 F.). Theresults of the series of tests are shown in graphic form in Figs. 1, 2,3 and 4 attached and indicate that in the case of this particularcombination of olen and aromatic that the greatest over-all efiiciencyin producing anti-knock gasoline boiling range hydrocarbons was obtainedby the use 'of an acid mixture' consisting of 40% sulphuric acid and 60%phosphoric acid, the phosphoric acid being of 85% concentration and thesulphuric acid being of the 96% grade.

Referring to Fig. l, it is seen that the volume increase of the benzollayer after passing in nbutylene for a period of three hours passedthrough a maximum when using an acid mixture of 60% phosphoric and 40%sulphuric acid'as stated, the yield dropping off sharply at either sideof this point.

In Fig. 2, curve A shows a maximumfor the particular mixture mentionedin the increase in weight of vthe hydrocarbon layer and curve B showsthat the weight increase of the acid layer (or in other words, theslu'dge formation) was still at a small value when the maximum weightincrease of benzol was obtained.

The curve in Fig. 3` shows the initial boiling point ofthe mixture ofalkylated hydrocarbons produced and indicates that the initial boilingpoint increases up to a mixture comprising 20% phosphoric and 80%sulphuric acid. Obviously, in the case of the two selected reactantsunder consideration the initial boiling point of the mnixture was due toresidual unaiected benzol.

Fig. 4 shows the percentage of material in the alkylated mixture boilingbelow 225 F., which temperature marks the usual upper boiling pointlimit allowable in present day gasolines. It is seen in this case thatfor the most desirable acid mixture in respect to yield of productionthat a certain percent of components boiling above the gasoline rangeare obtained. In this case the matter of economy would dictate a certainbalance between yield and quality of product.

While the foregoing example involving pure compounds is suilicientlyindicative of the accurate control of alkylation reactions which ispossible when using varying mixtures of vsulphuric and phosphoric acids,the process of the invention is adaptable to any case involving on theone hand mixtures of oleflns such as may be obtained when crackingeither gaseous or liquid hydrocarbons and, on the other hand, aromaticsor other reactive cyclic hydrocarbons. The factors of temperature,pressure, rate of introduction of the olens into contact with thearomatics and the acids may be adjusted to obtain the best results inany given case. Factors of major inuence are the chemicalAcharacteristics of the olens comprised in any commercial gas mixturewhich may be employed. When mono oleiins predominate, the percentage ofsulphuric acid in the acid catalyst mixture may in general be increased,since this will increase the speed of the reactions without producing anundue amount of polymerization; whereas, if the gas mixture contains arelatively large amount of highly reactive olens such as unsymmetricaliso-olens or di and tri-olens, the proportion of phosphoric acid may beraised.

The foregoing specification and the example and figures appended willserve to make clear the nature of the present invention in relation tothe art to which it pertains, but the particular data given is not to beconstrued in any sense as imposing undue limitations on its generallybroad scope.

I claim as my invention:

1. In the alkylation of cyclic hydrocarbons capable of condensation witholens, the improvement which comprises reacting the cyclic hydrocarbonwith the oleiin in the presence of a catalyst consisting predominantlyof a mixture of phosphoric and sulphuric acids in substantialproportions.

2. In the alkylation of cyclic hydrocarbons capable of condensation witholeflns, the improvement which comprises reacting the cyclic hydrocarbonwith a gaseous olefln in the presence of a catalyst consistingpredominantly of a mixture of phosphoric and sulphuric acids insubstantial proportions.

3. The method of producing alkylated derivatives suitable for use inmotor fuel, which comprises reacting an aromatic hydrocarbon of thebenzene series and boiling within the motor fuel range with agaseousolen in the presence of a catalyst consisting predominantly of a mixtureof sulphuric and phosphoric acids in substantial proportions.

4. The method of producing compounds suitable for use in motor fuelwhich comprises subjecting benzol at moderate temperature to the actionof an oleiinic gas in the presence o! a catalyst consistingpredominantly of a mixture of phosphoric and sulphuric acids insubstantial proportions.

5. The method of'producing compounds suitable for use in motor fuelwhich comprises treating an aromatic hydrocarbon of the benzene seriesboiling within the gasoline range, in the presence or a catalystconsisting predominantly of a mixture of phosphoric and sulphuric acidsin substantial proportions, with the oleilnic gas mixture produced inthe cracking of hydrocarbon oil, reacting olens contained in the gasmixture with the aromatic hydrocarbon under conditions to produce asubstantial quantity of'alkylated derivatives within the gasolineboiling range,-

andrecovering the gasoline boiling derivatives thus formed.

VLADIMIR. IPATIEFF.

